Conventional printed circuit boards (PCBs) typically have various components having different power inputs requiring different voltages. For a PCB with multiple electrical devices, each with potentially different voltage demands, power supplies having different output voltages are commonly used. These output voltages are typically selected to correspond to general voltage ranges that are used by the electrical devices of the PCB. Such an approach, however, consumes a rather large amount of energy, increases the difficulty of designing circuits, and also has a rather high cost. Currently, in order to accommodate many different voltage ranges, voltage regulators of rather large size are employed, and on-chip regulators are not a reality.
To decrease the amount of energy required, a common method has been to use multiple voltage regulators or converters to modify the voltage from a single power supply unit, to accommodate the needs of the electrical devices. These voltage regulators or converters allow the voltage that enters each electrical device to correspond to the device's working voltage.
The greater the number of different types of electrical devices on a PCB, the greater the number of corresponding voltage regulating devices, so that the supply voltages entering the electrical devices will fall in the correct voltage range. Such circuit designs, however, can utilize an overly high quantity of high-cost voltage regulator devices. Moreover, the electrical wiring between different voltage regulators must be separated, causing the need for more metal lines and therefore increasing total manufacturing costs. Needless to say, such circuit design may not be suitable or very economical for use in micro-scale electronic products. In addition, although the use of multiple voltage regulators in place of multiple power supply units can effectively reduce the amount of resources wasted, the large number of voltage regulators used to account for different electrical devices causes circuits on the PCB to become rather complicated. Because signals pass through a complicated arrangement of wiring, the signal response time is naturally longer and cannot be immediate, simultaneously lowering efficiency of power management. Also, the circuit design takes up a large portion of the PCB, which is an inefficient use of circuit routing.